Straight bar knitting machines and variable control means primarily applicable thereto



1963 R. BLOOD 3,073,138

STRAIGHT BAR KNITTING MACHINES AND VARIABLE CONTROL MEANS PRIMARILY APPLICABLE THERETO Filed Sept. 9, 1958 5 SheetsSheet l In ventor Awymm flM Attorney 5 Sheets-Shet 2 Jan. 15, 1963 BLOOD STRAIGHT BAR KNITTING MACHINES AND VARIABLE CONTROL MEANS PRIMARILY APPLICABLE THERETO Filed Sept. 9, 1958 In ventor Attorney Jan. 15, 1963 R, BLOOD STRAIGHT BAR KNITTING MACHINES AND VARIABLE CONTROL MEANS PRIMARILY APPLICABLE THERETO Filed Sept. 9, 1958 5 Sheets-Sheet 3 Jan. 15, 1963 BLOOD 3,073,138 7 R. STRAIGHT BAR KNITTING MACHINES AND VARIABLE CONTROL MEANS PRIMARILY APPLICABLE THERETO Filed Sept. 9, 1958 5 Sheets-Sheet 4 A torn e y R. BLOOD 5 Sheets-Sheet 5 MN WN NIL on W v l l I H HHI INHHIIIJNQ iUflEU l l l l l l l l LWl K i \R lnvenlor A ttorn e y STRAIGHT BAR KNITTING MACHINES AND VARIABLE CONTROL MEANS PRIMARILY APPLICABLE THERETO Jan. 15, 1963 Filed Sept. 9, 1958 United States Patent 3,673,138 STRAEGHT BAR KNlTTiNG MACHKNES ANE VARlAlilLE CQNTRGL PRHMARHLY APPLKCABLE THERETS Raymond Biood, Shepshed, England, assignor to Wiliiam Cotton Limited Filed Sept. 9, 1958, Ser. No. 759.9% Claims priority, application Great Britain dept. 11, 1957 11 Claims. 3!. 66-110) This invention is for improvements in or relating to straight bar knitting machines and varying control means primarily applicable thereto.

In these machines where a variable draw lever is provided to drive the thread carriers and slurcocks the adjusting screw of the draw lever is generally of the usual constant pitch type so that its adjustments, transmitted to it from the constant adjustments of the carrier stops, are themselves constant; however whilst this produces a lead (usually referred to as controlled lead or constant lead) of thread carriers over slurcocks, the constant adjustments of the screw gradually become less effective on the draw levers stroke as the leverage of the draw lever is lessened by the adjustments. The lessening of the leverage occurs in the usual manner since the adjustments of the screw cause displacement of a threaded slide block on it lengthwise of the draw lever. The draw lever is oscillated through this slide block from the usual draw cam, and the result is that the adjustments of the draw levers stroke are actually progressively decreasing so that, whilst it can be said that there is a control of the lead, such control is not strictly of the unvarying nature required.

in an endeavour to rectify this it has been proposed to make the draw lever screw of varying pitch which offsets the effect of the changing leverage on the adjustments and causes the draw levers adjustments to be unvarying whereby the required controlled or constant lead can be obtained. Evidently however a varying pitch screw has to be specially cut.

It has also been proposed to obtain the required controlled or constant lead by various means where the carrier drive is of chain and sprocket or positive type, but in this arrangement, the width of the fabric being produced corresponds to a length of the chain between spaced sprockets (narrowing being effected by inwards adjustment of the sprockets which decreases the length of the chain between them), and it is impracticable to adjust the sprockets sufficiently inwards to reduce the length of chain between them beyond a predetermined minimum determined by the diameter of the sprockets and therefore a limitation is imposed on the extent to which fabric can be narrowed.

An object of the invention is to enable a straight bar knitting machine (particularly of the type having means including a friction carrier drive which allows the knitting width to be narrowed from one extreme of a comparatively wide starting width to the other extreme of almost a point) to be operated with the required controlled or constant lead throughout the knitting (particularly between said extreme), by the provision of improved means which are particularly suitable for obtaining unvarying adjustments of the draw levers stroke.

The invention provides means for obtaining from adjustments of one value (e.g. thread carrier stop adjustments in a straight bar knitting machine) adjustments of predetermined different value (e.g. draw lever screw adjustments in said machine) comprising a rotatably ad justable member having a flexible element disposed on it to provide a helical variable motion transmitter surface, and a motion receiving member mounted to have imparted to it, by said surface, adjustments of a value "ice different in relation to the rotatable adjustments as predetermined by the helical variable motion transmitter surface provided by said flexible element. The invention also provides these means in or for a straight bar knitting machine and adapted for converting the constant adjustments of thread carrier stops to adjustments of a constant pitch draw lever screw, the latter adjustments being so varying as pre-determined by said surface as to produce the constant adjustments of the draw levers stroke required in obtaining constant lead of thread carriers over slurcocks.

Conveniently said flexible element is disposed on the rotatably adjustable member in a manner providing the helical surface on varying diameters, and the motion receiving member is a wheel adapted to have rotatable engagement with said element and be thereby adjusted from the rotatable adjustments of the rotatably adjustable memher. The flexible element may be a roller chain and the wheel may be a sprocket wheel. The rotatable adjustment member is conveniently a form having varying diameter surfaces (tag. as in a stepped cone) to support the flexible element at'its varying diameters. Conveniently the wheel is pivotally displaceable to rotatably engage with the varying diameters of the helical surfaces by being carried by an arm which is displaceable on a pivot, and conveniently there is a drive connection between the wheel and said pivot from which latter the adjustments can be transmitted. Conveniently also there is a rotatably adjustable lead screw parallel to the axis of the varying diameter surface, and said wheel is disposed to rotatably engage the different convolutions of said roller chain during its axial displacement by the lead screw. There may be a plate cam disposed in the axial path of displacement of said wheel for acting on the wheel to effect its pivotal displacement during its axial displacement. Conveniently the lead screw is rotatably adjustable by the rotatably adjustable member.

In the straight bar knitting machine the draw lever conveniently has co-operating with it a second draw lever with which a second similar means is associated to obtain required constant stroke adjustments of this second draw lever.

The invention also provides a straight bar knitting machine wherein the thread carrier drive is of the friction type enabling narrowing of knitting width to one extreme of almost a point when required. The draw mechanism comprises a draw lever which is driven through the intermediary of a second lever such that the draw lever can have a long stroke when required to enable knitting to be started at the other extreme of a comparatively wide starting width, and means adapted to cause the adjustmerits of the draw levers stroke to be unvarying and consequently the required control or constant lead to be obtained throughout the knitting between said extreme widths. One embodiment of the invention provides variable adjusting control means comprising a sprocket chain mounted helically and rigid on a roller-like form of predetermined contour and adapted to have input rotation imparted to it in each direction to a limit within the length of the chain, a sprocket wheel mounted for displacement in each direction parallel to the axis of the form and adapted to have rotation taken from it, and means to eifect the displacement of the sprocket wheel consequent upon the input rotation and whilst maintaining the sprocket wheel in continuous drive engagement with the chain so. that the output rotation is varied in relation to the input rotation to a value which is predetermined by the contour' of the form.

The above and other features of the invention set out in the appended claims are incorporated in the construction which will now be described, as a specific embodi ment with reference to the drawings accompanying the specification in which:

FIGURE 1 is a diagram illustrating the different effects of employing, in a straight bar knitting machine, a variable draw lever with constantpitch adjusting screw (a) in known manner and (b) according to the invention.

FIGURE 2 is a side sectional view of a variably adjusting control mechanism for the draw levers adjusting screw according to the invention;

FEGURE 3 is an end view of FIGURE 2 and partly in section.

FiGURE 4 is one end view of FEGURE 2.

FIGURE 5 is the other end view of FIGURE 2.

FIGURE 6 is a detail cross-section of part of FIG- URE 2.

FlGURE 7 is a general view of the draw mechanism.

FIGURE 8 is a cross-section of part of FIGURE 7.

Referring to FlGUREl this illustrates, at the left hand side, the effect, in a straight bar knitting machine, of a known type'of variable draw lever having a constant pitch adjusting screw. More specifically radial lines A represent the longitudinal axis of the draw lever, pivoted at B, to which motion is imparted from a draw cam through a link connection indicated at C which has a stationary pivot D and is connected to the draw lever?s screw, this point of connection being indicated at E.

Arcuate lines F indicate constant adjustments imparted to the screw from thread carrier stops in order to adjust the draw levers stroke (in addition to the adjustment of the thread carriers) for obtaining what is usually referred to as controlled or constant lead of thread carriers over slurcocks.

It will be seen from the plotted points of connection Ebetween the draw lever A and the link C that, whereas the arcuate lines F are equidistant, the lines A become progressively closer together between outer and inner exminimum width that it is required to knit, and any further reduction in knitting width has to be. accomplished without said control of the lead.

In any event when a chain-driven-type carrier drive is employed, the chair and sprockets impose a further limit to the minimum width of fabric thatcan be produced.

The invention seeks to make the adjustments of the draw lever unvarying, thereby not only to obtain the re quired controlled or constant lead but also to obtain knitting to a much narrower width, with the required controlled or constant lead throughout, and, to allow for this knitting to a less minimum width, a straight bar knitting V 5 and have angular ad ustments imparted to it from the machine is employed whichisof friction-carrier-drive yp '1 The right hand side of FIGURE 1 illustrates the un- V varying adjustments required of the draw lever, the lines "A being equidistant, and. to obtain this effect, bearing in mind that the linkCihas a stationary pivot D, a progressively'varying motion transmitting mechanism is provided by which constant adjustments of the carrier stops are converted into progressively varying adjustments of the draw levers screw as indicated by the arcuate lines E A progressively varying motion transmitting mechanism primarily for the purpose in hand is illustrated in detail in FIGURES 2 to dffrom. which it wil't be seen thatthere 'is a casing 1 having bearings for'an input shaft 2, to

anchored atthe narrow end of the form 3 by screw means 6 (see also FIGURE 6), and is also anchored at the other end of the form 3 by screw means 7. In between these anchorages 6, 7 the chain 5 extends in tight helical formation seated on the helical seating 4. The helical seating t provides, for this purpose, a raised helical face do on which the chain rollers 5a. are seated, and flanking helical recesses db in which the chain links 5b are seated; the seating surfaces of the helices do, 4b are parallel to the axis of the form 3 whereby the chain rollers do have their axes also parallel to the axis of the form 3, and the lateral walls of recesses 42) are perpendicular to this axis.

Meshing with this helical chain 5 there is a sprocket wheel 8 which, together with a second sprocket wheel 9, is mounted on a pivot pin ill) carried by an arm 11 pivoted on a shaft 12 mounted in bearings in the casing l.

The sprocke wheel 8 has a drive connection with the shaft 12 by the sprocket wheel 9 being connected by a chain 13 to a third sprocket wheel 14 mounted on the shaft 12 as best seen in PEG. 3.

The arm 11 is slidable along the shaft 12 (which shaft is parallel to the axis of the form 3) and for maintaining the drive connection between the sprocket wheel 8 and the shaft 12 throughout the sliding movement, the shaft 1 is splined and the sprocket wheel 14 is correspondingly splined.

During said sliding movement of arm 11, it is capable of pivotalmovement so that the sprocket wheel 8 can be maintained in mesh with the helical chain 5 from one end to the other thereof; for this purpose the arm 11 has a free bearing on the splined shaft 12, and the arm it carries a roller 15 at its free end which engages a curved ramp 16 which is fixed to the casing 1 and is parallel to the exterior of the form 3 in the longitudinal direction thereof.

For effecting the sliding movement of the arm 11 along the splined shaft 12 so that the sprocket wheel 8 follows the helical chain 5, the arm 11 has a forked tail 11a in the cleft of which there extends a tail part 17a of a screwnut-block 17, and the latter is screwed on to a constant pitch screw spindle 18 having bearings in the casing 1, and also extending parallel to the axis of the form 3.

The screw-nut block'is prevented from rotation by bearing faces 17b thereof engaging complementary faces on the casing.

The screw 18 is driven with the form 3 by a chain and sprocket connection, whereof the sprockets are shown at 19, 20.

Output adjustments are taken from the splined shaft 12 by gears 21, 2.2, the latter on an output shaft 23.

It will be appreciated that as constant rotational adjustments are imparted to the input shaft 2, the helical chain Sis likewise rotationally adjusted, and inaddition position of the arm 11 is adjusted parallel to the axis of the form 3 by the screw 18; these axial adjustments in addi-. tion to the action of the curved ramp 16 on the arm 11,

causes the sprocket wheel 8 to follow the helical chain helical chain 5. By virtue of the helical chain assuming the substantially conical shape of the form 3, the angular adjustments; of the sprocket wheel 8 are progressively varied in relation to the constant angular input adjustment of form 3 since the effective radius of chain 5 on the form 3 is different at axially spaced points of form 3.

.In the example illustrated, the form 3 is substantially conical, and has a slight concavity in such manner that the output adjustments are progressively varying.

Evidently the form} may be otherwise shaped to produce different characteristics in the output adjustments according to requirements.

In the primary application of this progressively varying motion transmitting mechanism, the output shaft, 23, which, being driven from the sprocket wheel 8 has corresponding progressively varying angular adjustments, has a drive connection with the adjusting screw of a variable draw lever in a straight bar knitting machine, while the input shaft has constant adjustments imparted to it from the thread carrier stops by the conventional thread carrier stop adjustment mechanism in the narrowing tackle of the machine. A transmission, for example a sprocket wheel and chain connection, connects the usual variable adjusting screw, on which the thread carrier stops are mounted for adjustment thereby, to the input shaft 2.

As a result of this it will be seen that, assuming the draw levers adjusting screw to have a constant pitch, the form 3 can be shaped, as shown, to cause the constant adjustment of the carrier stops to adjust the draw levers screw with progressively increasing adjustments; the result is that the adjustments of the draw levers stroke are unvarying in the required manner as illustrated by the lines A at the right hand side of FIGURE 1 whereby not only is the required controlled or constant lead obtained but it is obtained down to a minimum narrow width of knitting required. 7

A particular arrangement of variably controlled draw lever mechanism for the purpose in hand is illustrated in FIGURES 7 and 8.

This mechanism is primarily designed for a straight bar knitting machine employing a friction carrier drive by which knitting can be narrowed almost to a poin from acomparatively wide starting width.

More specifically there is provided a conventional draw lever 24 which is pivoted at 25 and is connected to the draw bar at26.

In straight bar. knitting machines, the draw bar is connected to the slurcock which controls the jacks ofthe sinkers. Furthermore, the draw bar is connected to a friction rod on-which is frictionally mounted a friction box with which a thread carrier rod mounting the thread carrier is releasably connected. As explained with reference to FIG. 1, adjustments of the draw lever of conventional straight bar knitting machines will not result in adjustments of the-slurcock and connected parts in constant increments. For imparting motion to the draw lever 24 it is connected by a link 27 to a second draw lever 28 which is pivotedat 29 and is connected by a link 30 to a follower lever 3 1 pivoted at 32 and driven by the draw cam 33. v

Conveniently the draw cam 33 operates between two follower rollers 34, 35, roller 34 being mounted on the follower lever 31 and follower roller 35 being on a follower arm 36 pivoted at 37 and which is coupled to the follower lever 31 by a link 38.

For adjustments of the draw levers stroke the draw lever 24 has a constant pitch adjusting screw 39, and also the second lever 28 has a constant pitch adjusting screw 49. Each screw 39, 40 has a screw nut 41, 42 on it and the link connection between the two levers 24, 28, is effected by pivotal connections 43, 44, of the link 27 to the screw nuts 41, 42.

Each adjusting screw 39, 40 is adjusted from the thread carrier selvedge stops through a progressively varying motion transmitting mechanism In, or 1b as described with reference to FIGS. 2 to 5.

The two mechanisms In and 1b are shown in FIG. 7 and include housings 1. The output shaft 23 of mechanism turns screw 39 of the draw lever 24, and the output shaft 23 of mechanism 1b turns screw 40 of the draw lever 28. The output shaft 23 of mechanism 1b carries a bevel pinion 23a meshing with the bevel pinion 23b on the spindle 230 which has a drive connection with the adjusting screw 40. Similarly, the output shaft 23 of mechanism 1a carries a pinion 23d meshing with a pinion 2342 on a spindle 23 which has a drive connection with screw 39.

The two mechanisms 1a, 1b have input shafts 2a, 2b adapted to be driven from the adjusting means of the thread carrier selvedge stops through meshing bevel gears 51, 51a on extensions 49, 50, respectively of the input shafts 2a and 2b, shaft 50 having a suitable drive cont nection with the adjusting means of the thread carrier selvedge stops.

Consequently, the adjusting screws 39, 40 of each draw lever is turned through varying angles by the mechanisms 1a, 1b, while the input shafts 2a, 2b of the mechanisms in, 1b are turned constant angles from the adjusting means of the thread carrier selvedge stops.

it will be appreciated that the ad ustment to the screws 39, 40 are simultaneous so that the link 27 is adjusted bodily along the screws, and that fabric can be knitted from a comparatively wide starting width to the other extreme of almost a point, and, by virtue of the variably adjusted screws 39, 40 the required constant lead is obtained throughout the knitting between said extremes.

Suitable speed control means may be provided by which the speed of the machine can be progressively increa ed from a minimum for the comparatively wide starting width of fabric, to a maximum speed at the other extreme of knitting almost to a point.

What I claim is:

1. Means for maintaining uniform lead of thread carriers over slurcocks in a straight bar knitting machine operable with varying strokes of the slurcocks and ineluding a constant pitch adjusting screw adapted to be aszociated with a draw lever, and a thread carrier stop adjusting mechanism, comprising a progressively varying motion transmitting mechanism having an input connection to be driven by the thread carrier stop adjusting mechanism and an output connection for transmitting output movements of the mechanism to the constant pitch adjusting screw.

2. Means for transmitting progressively varying rotation from uniform rotation comprising input and output drive transmitting members, a sprocket wheel having drive connection with one of said members, a substantially conical form having drive connection with the other member, and a chain secured helically around the form having drive connection with the sprocket wheel, and means for moving said sprocket wheel in axial direction of said form.

3. Means for maintaining uniform lead of thread carriers over slurcocks in a straight bar knitting machine operable with variable strokes of the slurcocks by including a constant pitch adjusting screw adapted to be associated with a draw lever, and a thread carrier stop adjusting mechanism, comprising a progressively varying motion transmitting mechanism having an input drive transmitting member to be driven by the threadcarrier stop adjusting mechanism, an output drive transmitter member for transmitting output movements of the mechanism to the constant pitch adjusting screw, a sprocket wheel having drive connection with tr e output member, a substantially conical roller-like form having drive connection with the input member, and a chain secured helically around the form and having drive connection with the sprocket wheel.

4. Means for effecting the conversion between constant rotational movements of a member and Varying rotational movements of another member, comprising rotatable input and output drive members, a sprocket wheel having drive connection with the output member, a helically disposed chain for drive connection with the sprocket wheel, a roller like form on which the chain is secured with a contour to suit the conversion required and which has a drive connection with the input member, means for displacing the sprocket wheel axially of thechain on the form, and a cam for moving the sprocket wheel to maintain it in drive engagement with the chain.

5. Means for effecting the conversion between constant rotational movements of a member and varying rotational movements of another member, comprising a mounted input drive shaft, a roller like form secured on the input drive shaft, a chain secured in tight helical formation round the form, a screw threaded shaft mounted parallel to the input drive shaft, drive transmitting means connecting the two shafts, a screw threaded block on the screw threaded shaft and having a tail part, a splined shaft mounted parallel to said two shafts, an arm on the splined shaft with one end having a cleft in which said tail part of said block projects and the other end carrying a sprocket wheel and cam foilower, drive transmitting means between the sprocket wheel and the spiined shaft, and a cam engaging the cam follower and matching the contour of the form.

6. A device as claimed in claim wherein the form is stepped to provide a helical seating for the chain with'the axes of the chain rollers parallel to the axis of the form.

7. In a straight bar knitting machine, the combination with variable draw mechanism which includes draw levers and constant pitch adjusting screws associated therewith and thread carrier stop adjusting mechanism, of means for maintaining uniform lead of thread carriers over 'SiUII'COCkS, said means comprising progressively varying motion transmittingdevices having input connections to be driven by the thread carrier stop adjusting mechanism, and output connections for transmitting output movements of the devices to the constant pitch adjustment screws.

8. In a straight bar knitting machine, the combination with variable draw mechanism, which includes a pair of draw levers each having associated therewith a constant pitch adjusting screw and thread carrier stop adjusting mechanism, of means for maintaining uniform lead of thread carriers over slurcocks, said means comprising a pair of progressively varying motion transmitting devices, one of these devices having an output connection for transmitting output movements of the device. to the adjusting screw of one of the draw levers, the other of said devices having an output connection for transmitting output movements of this device to the adjusting screw of the other draw lever, and each of said devices having an input drive connection to be driven by the thread carrier stop adjusting mechanism.

9. The combination as claimed in claim 8 having drive transmitting means connecting the two input drive connections and a single input drive connection from the thread carrier stop adjusting mechanism to said means.

10'. In a straight bar knitting machine having a draw 5.) Q bar and thread carrier stop adjusting mechanism, the combination of variable draw mechanism comprising a draw cam, a follower lever engaging the draw earn, a pair of adjustable draw levers one of which is connected to the draw bar, a link connecting the other of the draw levers to the follower lever, a pair of constant pitch ad usting screws associated with the adjustable draw levers respectively, a screw block on each adjusting screw, a link connecting the two screw blocks, and a pair of progressively varying motion transmitting mechanisms one of those mechanisms having an output con nection to one of said adjusting screws, the other having an output connection to the other of said adjusting screw and both mechanisms having an input member to be driven by the thread carrier stop adjusting mechanism.

11. Varying motion transmitting mechanism comprising a roller-like form of predetermined contour, a length of chain secured helically on the form, an input shaft on which the form is secured to have limited rotational movements imparted to it within the length'of the chain, a sprocket wheel mounted for displacement lengthwise of the form, and an output shaft having a drive connection with the sprocket wheel consequent upon the rotational input movements and whilst maintaining the sprocket wheel in continuous drive engagement with the chain, such that the rotational output movements are varied in relation to the rotational input movements as predetermined liy the contour of the form;

References Cited in the file of this patent UNITED s'rAras PATENTS 

1. MEANS FOR MAINTAINING UNIFORM LEAD OF THREAD CARRIERS OVER SLURCOCKS IN A STRAIGHT BAR KNITTING MACHINE OPERABLE WITH VARYING STROKES OF THE SLURCOCKS AND INCLUDING A CONSTANT PITCH ADJUSTING SCREW ADAPTED TO BE ASSOCIATED WITH A DRAW LEVER, AND A THREAD CARRIER STOP ADJUSTING MECHANISM, COMPRISING A PROGRESSIVELY VARYING MOTION TRANSMITTING MECHANISM HAVING AN INPUT CONNECTION TO BE DRIVEN BY THE THREAD CARRIER STOP ADJUSTING MECHANISM AND AN OUTPUT CONNECTION FOR TRANSMITTING OUTPUT MOVEMENTS OF THE MECHANISM TO THE CONSTANT PITCH ADJUSTING SCREW. 